Removal of undesirable projections (collectively referred to as “burrs” herein) from a surface, such as a metal or other relatively hard material, is important in the metal finishing industry, especially where presence of an unremoved burr can interfere with flow of a liquid or with the positioning of electrical charge-carrying lines. Producers of vehicles, such as automotive vehicles, water-borne vehicles and aircraft are especially concerned with burr removal on surfaces of tubes, cylinders and other containers and housings. However, many of the surfaces that contain burrs (referred to herein as “burred surfaces”) are relatively inaccessible, located in small spaces and cannot be de-burred by a conventional de-burring tool. For example, when two intersecting vias or apertures are drilled in a metal, breakthough of the drill for the second aperture into the space that is part of the first aperture will often produce a large metal burr at or near the intersection.
Further, in some situations two or different burr removal materials may be needed within a single container or housing. One example occurs where rough burr removal is to be followed by finishing, each requiring a different burr removal material or tool shape. Another example occurs when a container includes two or more different materials, each with a burred surface that requires its own burr removal mechanism and associated material.
When a burr removal tool is positioned to remove a burr, operation of the tool may unintentionally, and undesirably, contact and remove material that is preferably left intact. A burr removal tool often has a connecting rod extending between an abrasive nodule used for burr removal and a motor that provides mechanical movement of the nodule. Occasionally, the nodule briefly binds against the material to be removed, causing the rod to move laterally or in another uncontrollable manner.
What is needed is a burr removal tool that is flexible for reaching around obstructions and corners, can fit into relatively small spaces, provides two or more different burr removal materials in a single tool, and provides protection of a burred surface as the tool is moved into position for burr removal. Preferably, the tool should be small and flexible enough to permit rapid interchange of one type of burr removal mechanism by another. Preferably, the shape of the burr removal nodule should be chosen to minimize the amount of non-burr material that is removed. Preferably, motion of the shaft should be controlled to prevent occurrence of undesired excursions when the burr removal nodule temporarily binds against material being removed.